This invention relates to an improvement on a pre-existing electrical switch now used on various U.S. Army military vehicles under the designation MS 51113. The existing switch is employed to control current flow to vehicle lights, e.g., service lights (headlights), stop lights, blackout lights, parking lights, and instrument panel lights.
The existing switch comprises a housing structure mounted on the vehicle instrument panel. Three selectively actuable manual levers are carried on the front wall of the housing structure. One of the three levers operates a first selector switch element that controls current flow to the service lights, stop lights and blackout lights. A second lever operates a second selector switch element that controls current flow to the parking lights and instrument panel lights (bright or dim). The third lever functions as a lockout device for preventing movement of the first lever except when the third lever is deliberateley moved to an "unlock" position. The third lever prevents tampering of the switch mechanism by persons unfamiliar with switch structure operation. The third lever also prevents inadvertant switch adjustments due to external forces, e.g., vehicle vibration.
The present invention concerns simplification of the pre-existing switch structure. Under the present invention the "lockout" function is incorporated into the switch-actuating levers, thereby reducing the number of levers (from three to two). Principal result is cost reduction, although there may also be some operating benefits. With my improved arrangement the switch-actuating levers are susceptible to one-handed operation, whereas with the conventional arrangement two hands are required (one to depress the lockout lever and one to operate the switch lever). With the conventional arrangement soldiers sometimes attempted to permanently set the lockout lever in the "unlock" position (in order to make switch operation easier); often the switch structure was damaged in the process, thereby necessitating switch replacement.
Under my invention the "lockout" function is incorporated directly into the switch-operating levers. Each lever structure is designed to be successively movable in two senses, i.e., a push-in motion to "unlock", and a rotary motion to effect electrical switching. The two-direction motion can be accomplished with one hand.
As an ancillary feature I contemplate the inclusion of a "cycling" type circuit breaker into the switch housing. The circuit breaker is preferably a removable "drawer-type" structure that can be readily withdrawn through an opening in the front wall of the switch housing when the circuit breaker needs replacement.